Circuit Descriptions, Abbreviation List, and IC Data Sheets
9.
9.2
LCD Power Supply
The Power Supply Unit (PSU) in this chassis is a buy-in and is
a black-box for Service. When defective, a new panel must be
ordered and the defective panel must be sent for repair, unless
the main fuse of the unit is broken. Always replace the fuse with
one with the correct specifications! This part is available in the
regular market.
Three different PSU can be used in this chassis:
•
26 and 32 inch sets use a “Delta” PSU
•
37 and 42 inch sets use a “PPS” (Philips Power Solutions)
PSU
•
47 inch sets use a “Delta” PSU.
Figure “Overview of PSU connectivity” shows the connectivity
of the Power Supply Unit with the other panels in the set.
Figure 9-3 Overview of PSU connectivity
All Power Supply Units deliver the following voltages to the
chassis:
•
+24 V to the inverters
•
+12 V to SSB
•
+12 V and -12 V to Audio Supply
•
12 V to Bolt-on Supply (where applicable)
•
+5.2 V Standby voltage.
9.3
DC/DC converters
A switch generates the +5.2 V (+5V_SW) from the +5.2 V
(+5V_STANDBY) supply voltage. For LCD sets, this switch is
mounted on-board the SSB. For PDP sets, this switch is
mounted on the Power Supply Panel. This results in the
+5V_STANDBY (and +5V_SW for PDP sets) voltage(s),
coming from the Power Supply Unit, is (are) used as input for
the on-board DC/DC converters.
They deliver the following voltages to the board:
•
+3.3 V (+3V3_STBY)
•
+5.2 V (+5V_SW) (only for LCD sets)
•
+1.8 V (+1V8S_SW)
•
+34 V (+VTUN)
•
+3.3 V (+3V3_SW)
•
+3.3 V (+3V3_MOJO)
•
+1.2 V (+1V2_MOJO)
An overview can be found in figure “DC-DC converter block
diagram”.
Figure 9-4 DC-DC converter block diagram
9.4
Front-End
This chassis uses different tuners depending on the region and
execution. An overview of the different executions can be found
in table “Tuner diversity”.
Table 9-1 Tuner diversity
For a general outline of tuner applications in this chassis see
figure “Tuner IF diagram”.
Figure 9-5 Tuner IF diagram
In the LC7.1x chassis (analogue sets), the signal coming from
the tuner is fed to the IF demodulator (through the SAW filters)
and then passed to the Trident Video Processor.
9.4.1
Video IF Amplifier
The IF-filter is integrated in a SAW (Surface Acoustic Wave)
filter. In LATAM region, one filter (item 1161) is used for filtering
both IF-video and IF-audio. In other regions, the type of these
filters depends on the standard(s) received (region-
dependency). Some filters can be switched to another
standard, what makes them suitable for applications in multi-
standard platforms. An overview of the SAW filter diversity can
be found in table “SAW filter diversity”.
G_16860_051.eps
310107
Region
Tuner
Type
Europe
TD1316AF
hybrid
UV1318S
analogue
AP
UV1316E
analogue
China
TEDE9
analogue
Latam
UV1338
analogue
G_16860_063.eps
270707
(n.a. for LC7.xH)
(n.a. for LC7.xH)
(n.a. for LC7.xH)
Tuner
Video
SAW filter
Audio
SAW filter
Switch IC
IF Demodulator
CVBS
2
nd
SIF
Digital IF
36.16MHz
4MHz
RFAGC
RF AGC_analogue
I2C
IF AGC
Supply
+5V/+33V
RF AGC_digital
I2C_analogue
I2C_digital
G_16860_054.eps
020207